Little is known about the life cycle of the burrowing tortoise, although it is thought to live for up to 70 years and is classed as critically endangered.

Experienced keeper Andy Meek had to devise a husbandry protocol based on field data and the experiences of other collections.

He had to mimic the natural seasonal changes the adult animals would experience in the wild, with all the corresponding fluctuations in weather and diet.

This included spraying the tortoises with water to simulate rainfall.

One of the critical elements is a period of brumation – a state of dormancy during a cooler time of the year.

Mating tends to occur after this period. One single egg was laid and hatched after roughly 180 days of incubation.

An added complication in the process is that the egg needed a cooling period and was incubated by staff in a special custom-made incubator.

It is one of the world's smallest and rarest tortoises (Paignton Zoo/PA)

The single egg hatched on April 25 and the youngster will be reared by staff and then sent on to another zoo in due course.

Luke Harding, curator of lower vertebrates and invertebrates, said: “This is a great achievement for all the team, but I must congratulate keeper Andrew Meek – this is an excellent example of the hard work, evidence-based husbandry and attention to detail that brings success.

“Andrew was the lead on this project and did all the hard work and research on how to cycle the animals and incubate the eggs, including the crucial cooling period.

“Our success is down to the combination of particular husbandry and precise incubation. We also managed to deal with the complicated incubation process and changing the temperatures throughout.

“This species is not doing well in the wild. The more we can breed them and the more we can learn about their captive management and reproductive biology, the more we can contribute towards effective conservation measures in-situ.”